SERPENTINE AN IMPORTANT MEMBER OF THE UNSTRATIFIED ROCKS. 67 
great pressure, and exposed to intense heat, fusion would be the consequence ; but the ten¬ 
dency of the gas to escape under those circumstances must be great; and if, by some cause, 
passages should be opened into caverns in the earth, there would be an immediate escape of 
gas with great violence, and which, by pressure on itself, might cause large quantities to 
hquefy, by which the pressure would increase until some portion of the solid crust of the 
earth would be found to yield, and give exit to the pent up fluids. 
Another view of the subject may be presented, though it is strictly hypothetical, and per¬ 
haps there are but few data upon which to found even an hypothesis. It is supposed by 
many geologists of the present day, that during the early periods of the earth’s history, a 
much greater quantity of carbonic acid existed in a free state than at the present time; and 
that it was owing to this abundance of the material, so essential to the growth of plants, that 
we are to attribute the great preponderance of some vegetable forms over those of the present 
day. Admitting the fact, by what means can we account for such a condition, other than by 
bringing in the aid of limestone ignited by the more powerful operation of the elements in 
those early periods, and for the existence of which we find so many indubitable proofs ? 
However visionary these views may appear to others, to myself they are rational; and if 
admitted, they explain phenomena and facts of ancient dates in a way more clear and full 
than the ordinary hypotheses of the day. Although it is maintained in one of the most popu¬ 
lar geological systems, that the powers of nature are as active and energetic at the present as 
in ancient periods, still, after a survey of the whole subject, and of the evidence- on which 
those views rest, doubts of .their correctness remain in the minds of most geologists. • That 
a more quiescent state should now prevail, and that the former violence of the elements 
should be restrained, or rather become more feeble by a more equable balance of the forces 
which act and react on each other, is agreeable to reason, and the benevolence of the Great 
Architect of the Universe. 
4. Serpentine. 
Throughout the whole of the northern primitive district, serpentine forms an important 
member of the unstratified rocks. It is not to be understood, however, that it covers large 
areas, or forms mountain masses; but that it is of frequent occurrence, holds important rela¬ 
tions, and in an economical point of view, is well worthy of consideration. 
In giving a detailed account of a formation, or a particular rock, one very interesting view 
in which it is to be placed, is its resemblance to, or difference from, the rocks of the same 
species in other sections of the country. By this course, we are able to discover those causes 
which seemed to have operated in the production of those differences, or to have preserved 
their similarity ; and besides this, we are aided in building up a rational and satisfactory 
theory of the formation of the earth. 
Pursuing our geological investigations in different sections of the country, one fact is 
brought to light, viz. that rocks of the same name, and very properly considered the same 
species, do in fact present many remarkable'differences. Granite and serpentine, for instance. 
